textproduct: Quad Cities

KEY MESSAGES

- Above normal temperatures remain forecast through the period with high temperatures peaking in the lower to mid 90s Tuesday through the end of the week. There is a 10 to 20 percent chance of heat indices over 100 Tuesday through Thursday.

- Forecast remains dry through Thursday with low chances of rain Friday and Saturday.

SHORT TERM /THROUGH TUESDAY/

Issued at 141 PM CDT Mon Jul 13 2026

High pressure at the surface and aloft remains in place over eastern Iowa. This position of high pressure is confidently going to be remaining there through at least Wednesday morning and possibly through Thursday before significant changes occur aloft. Though deep moisture remains well south of the region, boundary layer moisture has increased from yesterday's dew points in the lower to mid 60s to more common mid to upper 60s today. While more humid feeling than yesterday at Noon, these values remain well below most model data for 2m dew point forecasts today.

Certainly we're in the doldrums under this upper level high, and surface high pressure. Winds remain very light, and skies mostly sunny, though a bit of cumulus is developing today in our southern 1/2 of the area. It appears we're headed for highs in the 90-92 range for most areas today, which is 1-2 degrees below NBM forecasts. Lows tonight will be a degree or two higher than last night, mainly due to moisture increase through evapotranspiration.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 141 PM CDT Mon Jul 13 2026

Heat headlines (advisory) remain possible through late week. That said, our forecast remains consistent in showing the upper high overhead through Wednesday, then a subtle shift west Thursday and Friday, followed by more confidence in a western push of the high / ridge for Saturday and beyond. While broad support exists for highs in the lower 90s, with nearly 95% of NBM going over 90 through Thursday, the 50th percentile remains in the 92-96F range in the period, and given our light flow beneath the high, slightly under- performing temperatures, we continue to cap highs at 94/95 through mid week, as the NBM has hot spots in the 96+ most days this week. Dew point values will increase through evapotranspiration, which is nearing seasonal peaks. However, that is the primary moisture source for this high pressure, and we will lack other typical moisture sources near the center of high pressure. The moisture levels will be an important feature in the week ahead, as it is certainly the deciding factor in heat headlines. For now, widespread mid 60s to low 70 dew points remain forecast, resulting in afternoon heat index of 94 to 100 for many days this week, but most confidently on Tuesday through Thursday. LREF probabilities of heat indices exceeding 100 remain in the 10 to 20 percent range during this period for any one location.

Beyond Thursday, the greater spread in model data is showing up with highs as cool as the mid 80s in the lower 25% of NBM guidance late in the week into the upcoming weekend, but the NBM 50% remaining in the lower to mid 90s. No matter what, we're still very much in a warm pattern through the end of the week ahead, and heat headlines remain a possibility.

Rainfall is now seen in several deterministic models for late week's backdoor front. However, looking at those models, they have extremely high dewpoint values in place, typical of deterministic output.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1211 PM CDT Mon Jul 13 2026

Patchy MVFR/IFR valley fog development will remain possible again late tonight, but probabilities for impact at the terminals are far too low for any mention. Otherwise, VFR conditions look to abound with light winds.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.